Dynaco FM3 2X 555001 & 555004 PEC Modules – $79.00CAD
Scroll to the bottom if you would like to download the assembly manual as a PDF.
This kit for the Dynaco FM3 replaces the two 555001 and one 555004 PEC boards. The capacitors are 500V Silver Mica types and the resistors are PRP Precision 1% Resistors from Parts Conexxion.
This is a kit, you need to solder it together and into the FM3.
Assembly:
There are two of the 555001 PEC boards and one of the 555004 to be assembled and installed.
Parts List:
555001 PEC BOARD X2
555004 PEC BOARD
For the capacitors you can use 500V Silver Mica or Polystyrene. I have always used the Silver Mica, but they are getting harder to find and more expensive. The resistors are all 1/2W and at least 1% tolerance.
Solder the components into the outlined positions. Do not leave the leads too long as the 555001 boards are quite close together when soldered to the board.
Use some cut component leads or some stiff solid wire to make the leads for the boards. Solder them into holes 1,2 & 3 on each board then bend them 90°. Cut the leads to about 1” for the 555001’s and a bit shorter for the 555004.
Open your FM3 taking off the cage and bottom. You will find the 555004 PEC near the 12AX7 V-7 tube on the long skinny circuit board PC-8
Flip the FM3 upside down and unsolder the 3 leads. You may have to use a solder sucker as the FM3 boards have a lot of solder on them. Be careful with how much pressure you put on the old PEC modules. Do not rock them back and forth when you are taking them out as the traces on these old boards are easy to lift. Use the solder sucker and then a de-soldering wick. The module should drop out without having to pull it. Once the old PEC module comes out just solder in the new one with Pin 1 in Hole 1 etc. If you did lift a trace suck all the solder off it and clear out the hole. When you solder in the new PEC solder that lead last and hold it against the PCB with a flat head screwdriver.
The two 555001 PEC modules are located on the corner of PC-12 circuit board on the corner by the 6BL8 tube V71.
The leads on the 555001’s need to be a bit longer as they need to bend over a bit to prevent the two from touching. Solder them in and bend them so they are not hitting each other. If they are too close and you are worried about them touching, use some Kapton or electrical tape on the back of each. You could also build one board with the components on the opposite side from the silkscreening. It’s no like they move around so I do not worry too much about them.
